The present invention relates to a data logging device for monitoring and recording information from a plurality of remote transducers to which the data logging device is attached. More particularly the invention relates to such a device that can record details of processing conditions such as temperature, pressure, humidity, specular gloss, thickness etc. in a variety of different manufacturing processes, but the invention is not limited to devices restricted to such use and may be used for example in the measurement of strain, stress etc. on bridges or other structures.
The accurate measurement and recording of conditions during a manufacturing process is a requirement in many industries and, historically this need has been served by systems based on clockwork or electromechanical chart recorders or simple cassette recorders. These systems have posed several problems. Generally these devices are "dumb" recorders that are quite large and fragile and require frequent attention to reload batteries and charts or for rewinding. Moreover in many cases the data so collected does not lend itself to easy analysis particularly when a specific event needs to be analysed in detail.
More recently, portable, battery operated devices using microprocessors have been proposed. However, such devices are often complex to use, requiring operation of switches to set particular functions and parameters and thus an understanding of the device that may be beyond the ability of an unskilled or semi-skilled person. Moreover such devices are often task-specific and do not lend themselves to use in a variety of different situations.
Accordingly there is a need for a portable data logging unit that is simple to use, but which, at the same time, is capable of monitoring and storing large amounts of data for subsequent study.